<?php 
class Thaind_Auth extends Zend_Auth
{
    protected function __construct(){
        $this->setStorage(new Zend_Auth_Storage_Session(get_class($this)));
    }
	public function getStorage()
    {
        if (null === $this->_storage) {
            $this->setStorage(new Zend_Auth_Storage_Session(get_class($this)));
        }

        return $this->_storage;
    }
	public static function getInstance()
    {
        if (null === self::$_instance) {
            self::$_instance = new static();
        }
        return self::$_instance;
    }
}